ICs for FM/AM Tuner
1
AN7298FBP
FM-IF, NC, and MPX IC for car radio
s
Overview
The AN7298FBP is an IC for car radio. The FM-IF,
NC (Noise Canceler) and MPX functions are integrated
into a single chip. The IC has the higher functions than
our conventional IC (AN7292NSC) and the characteris-
tics of multi-pass detection, mute and SD functions are
improved.
s
Features
IF sensitivity is high. (limiting sensitivity 26 dB
)
Adjustment-free VCO (912 kHz)
Good linearity of S-meter output (adjusting funciton)
s
Applications
Car radios
QFH048-P-1212
Unit: mm
48
37
13
24
1
14.20.4
12.00.3
0.30.1
0.8
14.20.4
12.00.3
(0.55)
0.10.1
2.80.2
1.30.1
1.30.1
0.15
+0.10
0.05
12
36
25
AN7298FBP
ICs for FM/AM Tuner
2
s
Block Diagram
2nd
limiter
Reg.
V
cont
det.
V
cont
DC amp.
1st
limiter
Multipath
detector
ASC .ATC
stereo
demod.
Pilot
det.
Divider
VCO
Pilot
canceler
PNL
Pulse det.
AGC
Mute amp.
Quad det.
AFC amp.
Band det.
SD
IF count.
24
23
22
21
20
19
18
17
16
15
14
13
37
38
39
40
41
42
43
44
45
46
47
48
1
2
3
4
5
6
7
8
9
10
11
12
36
35
34
33
32
31
30
29
28
27
26
25
GND
V
CC
ICs for FM/AM Tuner
AN7298FBP
3
Pin No.
Description
1
ASC adjustment
2
ATC adjustment
3
Separation adjustment
4
ATC LPF
5
R-ch. output
6
L-ch. output
7
Control voltage output
8
Band mute control
9
Soft mute filter
10
Phase detection filter1
11
Forced monaural
12
Phase detection filter 2-1
13
SD startup time constant setting
14
Phase detection filter 2-2
15
VCO
16
Phase detection filter 3
17
Pilot canceler negation filter
18
PNL LPF
19
PNL LPF
20
PNL gate pulse filter
21
PNL AGC
22
PNL input
23
PNL HPF
24
IF-counter output stop
Pin No.
Description
25
IF detection output
26
PNL output hold
27
SD/IF counter output
28
SD sensitivity adjustment
29
AFC output
30
V
CC
31
IF detection coil
32
Limiter output
33
Soft mute adjustment
34
Stereo lamp drive
35
2nd limiter output
36
GND
37
Mute adjustment
38
1st limiter
39
Reference voltage
40
1st limiter output GND
41
1st limiter bias
42
IF input
43
Mute slope adjustment
44
Control voltage adjustment
45
Control voltage output
46
Control voltage input
47
ASC
48
Control voltage detection
s
Pin Descriptions
s
Absolute Maximum Ratings
Parameter
Symbol
Rating
Unit
Supply voltage
V
CC
9.7
V
Supply current
I
CC
48
mA
Power dissipation
*2
P
D
301
mW
Operating ambient temperature
*1
T
opr
-
30 to
+
80
C
Storage temperature
*1
T
stg
-
55 to
+
125
C
Note) *1 : All parameter values except for the power dissipation, the operating ambient temperature and the storage temperature are
T
a
=
25
C.
*2 : Power dissipation of IC alone at T
a
=
80
C.
AN7298FBP
ICs for FM/AM Tuner
4
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Control voltage 1
V
C1
Without input, pin 45 DC voltage
0.05
0.50
0.90
V
Control voltage 2
V
C2
V
IN
=
40 dB
, pin 45 DC voltage
1.20
1.65
2.10
V
Control voltage 3
V
C3
V
IN
=
70 dB
, pin 45 DC voltage
2.75
3.45
4.15
V
Control voltage 4
V
C4
V
IN
=
100 dB
,
pin 45 DC voltage 4.45
5.35
6.25
V
Control voltage 5
V
C5
V
C5
=
V
C3
-
V
C2
1.60
1.80
2.00
V
Control voltage 6
V
C6
V
C6
=
V
C4
-
V
C3
1.70
1.90
2.10
V
AFC offset voltage
V
AFC
Without input, DC voltage between
-
0.1
0.0
0.1
V
pin 29 and pin 39
Output level L
V
OL
V
IN
=
70dB
, pin 6 AC voltage
90
110
130
mV[rms]
Output level R
V
OR
V
IN
=
70dB
, pin 5 AC voltage
90
110
130
mV[rms]
Channel balance
CB
CB
=
20Log (V
OL
/V
OR
)
-
1.0
0.0
1.0
dB
Limiting sensitivity
V
lim
V
OL
to 0 dB. Input when pin 6
20.0
26
30.0
dB
AC voltage drops by 3 dB
Residual pilot voltage
V
PC
Pin 26 output when V
IN
=
70 dB
,
4
14.0 mV[rms]
pilot signal 10% modulation
Stereo lamp on-level
Lamp
ON
Modulation with pilot signal only,
1.0
3.5
6.0
%
DC voltage of pin 34 is below 2 V
Stereo lamp off-level
Lamp
OFF
Modulation with pilot signal only.
2.0
6.0
10.0
dB
Ratio of stereo lamp on and off
level
Separation L-ch.
Sep
L
V
IN
=
70 dB
, L
+
R
=
90%
25
33
dB
Pilot 10%
Separation R-ch.
Sep
R
V
IN
=
70 dB
, L
+
R
=
90%
25
33
dB
Pilot 10%
Capture range
CR
V
IN
=
70 dB
,
+
0.6
+
0.8
%
pilot signal 6.5% modulation
-
0.2
0.4
Counter output level 1
V
IF1
V
IN
=
70 dB
, pin 28
=
0V,
0
2.0
5.0
mV[rms]
pin 27 10.7 MHz, output voltage
Counter output level 2
V
IF2
V
IN
=
70 dB
, pin 28
=
V
CC
,
85
100
115
mV[rms]
pin 27 AC output voltage
Power supply current
I
tot
Without input, pin 11
=
0 V
28.0
35.0
42.0
mA
Monaural THD (L-ch.)
THD
L
Monaural input 400 mV, 1kHz,
0.15
0.3
%
L-ch. distortion
Monaural THD (R-ch.)
THD
R
Monaural input 400 mV, 1kHz,
0.15
0.3
%
R-ch. distortion
s
Electrical Characteristics at V
CC
=
8 V, f
IN
=
10.70 MHz, f
mod
=
1 kHz 30%FM, T
a
=
25
C
s
Recommended Operating Range
Parameter
Symbol
Range
Unit
Supply voltage
V
CC
7.2 to 9.6
V
ICs for FM/AM Tuner
AN7298FBP
5
s
Electrical Characteristics at V
CC
=
8 V, f
IN
=
10.70 MHz, f
mod
=
1 kHz 30%FM, T
a
=
25
C (continued)
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
Stereo THD (L-ch.)
THD
SL
Stereo, L
+
R
=
360 mV,V
P
=
40 mV,
0.15
0.3
%
L-ch. distortion
Stereo THD (R-ch.)
THD
SR
Stereo, L
+
R
=
360 mV,V
P
=
40 mV,
0.15
0.3
%
R-ch. distortion
AGC voltage 1
V
AGC1
Input
=
0, R
S
=
600
,
0.0
0.4
V
pin 21 DC voltage
AGC voltage 2
V
AGC2
Input V
IN2
=
2 mV[rms],
1.3
1.48
1.65
V
150 kHz, pin 21 DS voltage
Noise detection voltage
V
DET
V
IN2
=
100 mV[rms],150 kHz,
0.0
0.3
V
pin 20 DC voltage
Gate pulse width
PW
V
IN2
=
0.3 V[p-p], t
W
=
1
s,
19
24
29
s
f
=
1 kHz, pin 26 output pulse width
Residual noise voltage
V
NR
V
IN2
=
1 V[p-p], t
W
=
10
s, f
=
1 kHz,
0.0
1.2
mV[rms]
input through LPF, L-ch. output
SD bandwidth
SDW
Bandwidth when SD output (pin
110
140
170
kHz
27) is over 4.5 V, V
28
=
2.7 V
SD sensitivity
SDS
Input when SD output (pin 27) is
45
55
65
dB
over 4.5 V, V
28
=
2.7 V
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